According to Life & Style magazine, the ring is "a huge emerald-cut diamond," "a rectangle with tapered diamond baguettes on the sides."

After the actress said "yes!" the pair got on the phone with their respective families to deliver the good news.

"Justin Theroux had an amazing birthday on Friday, receiving an extraordinary gift when his girlfriend, Jennifer Aniston, accepted his proposal of marriage," a rep for the "Wanderlust" actor told People magazine.

"Everyone is really excited for them," the source told People. "It's amazing to see how happy Justin makes Jen, and everyone was always hoping that he would propose."